Yes they are working at the same rate because 4x5=20 and 10 windows every four hours and 5x10= 50 so they are both working at the same rate. Or here is another answer, They are working at the same rate because one was doing 10 windows every four hours and one did 50 windows in 20 hours, so 4 x 5= 20 which is the amount of hours the other carpenter was doing so 5x10 for every four hours, and that equals 50 so they were both working at the same rate. Hope I helped :)
